High-performance batteries can serve as part of a solution to supply and storage problems as well as environmental issues related to the replacement of fossil-fuel-based energy with clean alternative energy. Rechargeable batteries (also called secondary batteries) are an essential tool on the way to achieve this goal.
Rechargeable batteries differ from their non-rechargeable counterparts in that they may be connected to an electricity supply, such as a wall socket, be recharged and used again. In rechargeable batteries, each charge/discharge process is called a cycle. Rechargeable batteries eventually reach an end of their usable life, but typically only after many charge/discharge cycles.
Currently, rechargeable lithium-ion (Li-ion) batteries are the most widely used rechargeable batteries. Existing Li-ion batteries are based on LiCoO2 cathodes and graphite anodes. This leading Li-ion battery technology is based on intercalation reactions and is believed to be limited to a theoretical specific energy density of ˜370 Wh kg−1 and theoretical specific capacity <200 mAh g−1 for the LiCoO2/graphite.
Rechargeable lithium-sulfur batteries (Li—S), on the other hand, are of interest because of the high theoretical specific energy density (2600 Wh kg−1), high theoretical specific capacity (1680 mAh g−1), low material cost, and low safety risk that they possess.
However, lithium-sulfur batteries suffer from a number of drawbacks such as (1) leakage of sulfur and polysulfides from the host during discharge process; 2) poor control over the free volume that shall be in place inside of the cathode materials to accommodate the large volume expansion of sulfur by lithiation during discharge process (formation of Li2S, corresponding to ˜78.7% of volume expansion); and 3) poor electrical conductivity of the bulk sulfur. All these factors will lead to capacity fading and poor cyclability of the lithium-sulfur batteries. These disadvantages cannot be resolved by the current available methods to form such rechargeable lithium-sulfur batteries.
There is therefore a need to provide a method of forming a component of a rechargeable battery that overcomes, or at least ameliorates, one or more of the disadvantages described above.